Oven-thermometer.



A. E. .WHITTIER. OVEN THERMOMETER. APPLICATION FILED 1143.1, 1911.

Patented Sept. 12,1911.

COLUMBIA PLANDGRAPM CD..WASMINGTON, I). c.

UNTTED STATES PATENT OFFICE.

ALBERT E. WHITTIER, OF BRISTOL, CONNECTICUT.

OVEN-THERMOMETER.

Specification of Letters Patent. Patented Sept. 12, 1911.

Application filed March 1, 1911. Serial No. 611,721.

To all whom it may concern:

Be it known that I, ALBERT E. T/VHITTIER, a citizen of the United States, residing at Bristol, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Oven-Thermometers, of which the following is a specification.

This invention relates to those devices which are designed to be located in openings in the walls of the ovens of wood, coal, gas, oil and electric stoves and ranges, for the purpose of indicating the temperature in the interior in order that baking, roasting and other cooking may be done with certainty and exactness, and with a consequent saving of time and fuel and the production of more uniformly palatable food.

The object of the invention is to provide a metallic thermometer for such purpose, which is small, has few parts that are easy to form and simple to assemble, and which is very sensitive, accurate and cheap, whereby a high class article may be furnished at a low cost.

Figure 1 of the accompanying drawings shows a front view of a thermometer which embodies this invention. Fig. 2 shows a plan of the back-plate and the active mechanism; the casing, pointer and dial being omitted from this view. Fig. 3 shows a section on the plane indicated by the dotted line 3-3 on Fig. 1. Fig. 4 is a view looking edgewise at the parts shownin Fig. 2.

The back-plate 1 is desirably punched from thin sheet iron or steel with an ear 2 on each side. These ears are perforated for the passage of the bolts or screws which are used to secure the device in place. Fastened to the front of the back plate at the centeris a bobbin-shaped dial support which is formed of a disk 8, that is designed to be riveted or otherwise fastened to the backplate, a stud 4t and a disk 5 to which the dial 6 is fastened by screws 7. The two disks which form the ends of the dial-support are desirably placed upon reduced ends of the stud, which ends are then headed over so as to make the structure rigid. The dial may have any desired graduations, and lettering, or other indications, such as the numbered segmental scale 8, for indicating the degree of heat.

Secured by rivets or other means to the back-plate is a metallic strip 9. An end of this strip is turned up to provide a standard 10. One end of a thermometric arm 11 is secured to this standard. This thermometric arm is formed of two pieces of metal having different co-efficients of expansion when heated, such as copper and steel. These, tightly fastened together, extend near the back-plate in a curve from the standard,

. around the bobbin, and terminate adjacent todthe end of the strip opposite the standar A portion of the strip 9 is raised to form a bridge 12. Supported by the walls of an opening through this bridge, and by a bearing 13 secured to the baclcplate, is an arbor 14. This arbor extends outward through the dial, and fixed on its outer end is the pointer 15, which moves across the graduated scale on the dial for indicating the temperature in the oven. Fastened to the arbor, so as to turn it, is a lever 16. The inner end of this lever extends beneath the bridge and is adapted to engage the inner surfaces of the side walls thereof. One end of a link 17 is pivoted to the outer end of the lever, while the other end of the link is connected with the free end of the thermometric arm. This actuating and indicating mechanism is protected by acasing that is formed of a cylinder 18 which has an integral flange 19 at one end, the ring and flange being desirably blanked from thin sheet steel or iron. The casing is secured in position by rivets 20 which extend through the flange and the back-plate. The glass front 21 is held in place by the cap ring 22.. It is customary to insert a trimming band 23 inside of the casing below the cover, for the purpose of improving the appearance.

The dial supporting bobbin and the bridge strip bearing the thermometric arm, lever, arbor and link which connects the lever with the arm, are secured to the back-plate and the arm adjusted. The dial is then fastened in position, and after the pointer is fixed on the arbor, the casing with the cover is placed over the mechanism and secured to the back-plate.

This structure has but a single fiat sheet of thin metal at the back, separating the actuating parts of the device from the oven. There are very few parts, and these can be assembled before being attached to the backplate. After the actuating parts are adjusted and the dial fastened, the casing is put in place and secured. The thermometric arm in this structure is only separated from the oven by a thin sheet of metal having easy to assemble.

good heat conductivity, and consequently it is very sensitive. The few parts composing the structure are very cheap to form and The thermometric arm can be attached to the bridge strip, and, through the link and lever, to the spindle before the bridge strip is secured in place. All of the adjustments may be made before the casingis placed in position.

In practice it has been found that, this Very simple mechanism is exceedingly sensitive' and quite accurate, both when the temperat ureis risingand fallingin the-oven of metal baclcplate, a strip, having a portion raised to form a bridge and one end turned up to form a standard, secured to the front ofthe back-plate, an arbor supported by the 20 the lever, a bobbin secured to the front of 2 the back-plate, a dial fastened to said bob- ,bill, a pointer fixed to the arbor and movable lacross the dial, and a casing secured to the @back-plate over the aforesaid actuating and indicating parts.

ALBERT E. lVI-IITTIER. Vitnesses:

BEATRICE S. BETTON,

GEO. PRIEST.

ca i'es oftlii s' patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

